Polyurethane resin aqueous dispersion and sheet material obtained from the same

ABSTRACT

The present invention provides an isocyanate group terminated prepolymer aqueous dispersion (A) that is composed of water and an isocyanate group terminated prepolymer (a) dispersed in the water, whose content in the (A) is in a range of 60 wt % to 85 wt %, wherein the (A) optionally contains a-surfactant in a range of 0 wt % to 10 wt % based on a weight of the (a), and a solvent in a range of 0 ppm to 5,000 ppm based on the weight of the (a). The present invention also provides a polyurethane resin aqueous dispersion (B) that is composed of a polyurethane resin (b), whose content in the (B) is in a range of 20 wt % to 65 wt %, wherein the (b) is obtained by a chain extension reaction of the (A). The present invention is capable of providing a polyurethane resin aqueous dispersion having excellent storage stability. The aqueous dispersion can be used in a polyurethane resin sheet material, a paint, an adhesive, a tackiness agent, or a fiber-treating agent that has less flammability, a high level of safety to the human body, and environmental friendliness, and is effectively applied in a leather-like polyurethane resin sheet material in which migration is prevented.

TECHNICAL FIELD

The present invention relates to an aqueous dispersion in which aprepolymer terminated with an isocyanate group is dispersed (hereinafterreferred to as isocyanate group terminated prepolymer aqueousdispersion), and a polyurethane resin aqueous dispersion. The presentinvention particularly relates to a polyurethane resin aqueousdispersion for use in sheet materials, paints, adhesives, and agents fortreating fibers.

BACKGROUND ART

Conventionally, in the production of polyurethane resin aqueousdispersions, organic solvents have been used for decreasing viscosities.However, recently, the use of organic solvents has raised problems fromthe viewpoints of the flammability of organic solvents, the safety tothe human body, the impact on the environment, etc. To cope with theproblems, a method for producing a polyurethane resin aqueous dispersionwithout using an organic solvent has been proposed (for instance,JP-A-3(1991)-149214).

However, the polyurethane resin aqueous dispersion produced by theforegoing method contains many polyurethane resin particles havingrelatively large particle diameters. The particles tend to settle, andtherefore, the foregoing material has a problem in storage stability.

It is an object of the present invention to provide a polyurethane resinaqueous dispersion having excellent storage stability.

It is another object of the present invention to provide an isocyanategroup terminated prepolymer aqueous dispersion for achieving theabove-described object.

It is still another object of the present invention to provide anisocyanate group terminated prepolymer aqueous dispersion and apolyurethane resin aqueous dispersion, which does not contain, orcontains a small amount of, a surfactant and a solvent.

It is still another object of the present invention to provide apolyurethane resin sheet material, a paint, an adhesive, a tackinessagent, or a fiber-treating agent having less flammability, a high levelof safety to the human body, and environmental friendliness.

It is still another object of the present invention to provide apolyurethane resin sheet material, a paint, an adhesive, a tackinessagent, or a fiber-treating agent possessing excellent waterproofness.

It is still another object of the present invention to provide aleather-like polyurethane resin sheet material in which resin migrationis prevented.

SUMMARY OF THE INVENTION

An isocyanate group terminated prepolymer aqueous dispersion (A) of thepresent invention comprises water and a prepolymer (a) terminated withan isocyanate group, the (a) being dispersed in the water, a content ofthe (a) in the (A) being in a range of 60 wt % to 85 wt %, wherein the(A) either does not contain a surfactant or contains a surfactant of notmore than 10 wt % based on a weight of the (a), and either does notcontain a solvent or contains a solvent of not more than 5,000 ppm basedon the weight of the (a).

A method of the present invention for producing an isocyanate groupterminated prepolymer aqueous dispersion (A) comprises the step ofsubjecting the (a) and water to contact mixing by employing a kneaderhaving an operation power of not less than 20 KW/m³ so as to dispersethe (a) in the water, wherein the (a) either does not contain asurfactant or contains a surfactant of not more than 10 wt % based on aweight of the (a), and either does not contain a solvent or contains asolvent of not more than 5,000 ppm based on the weight of the (a).

A polyurethane resin aqueous dispersion (B) of the present inventioncomprises a polyurethane resin (b) obtained by causing the foregoing (A)to further undergo a chain extension reaction, the content of the (b)being 20 wt % to 65 wt %.

A method of the present invention for producing the (B) comprises thestep of causing the chain extension reaction of the (A) by employing atleast one dispersing machine selected from the group consisting of astator/rotor dispersing machine, an ultrasonic dispersing machine, ahigh-pressure impact dispersing machine, and a vibration-mixingdispersing machine.

A polyurethane resin aqueous dispersion for use in a sheet material (B1)of the present invention comprises a polyurethane resin that is ananionic polyurethane resin (b1) having at least one group selected fromthe group consisting of a —COO^(—)group and —SO₃ ^(—)group, the groupbeing in a range of 0.01 wt % to 8 wt % based on a weight of thepolyurethane resin, wherein the polyurethane resin contains a nonionicsurfactant having a HLB of 10 to 18, in a range of 0.1 wt % to 10 wt %based on the weight of the polyurethane resin, and an inorganic salt ina range of 0.1 wt % to 10 wt % based on the weight of the polyurethaneresin, and the (B1) either does not contain a solvent, or contains asolvent of not more than 5,000 ppm based on the weight of thepolyurethane resin.

A sheet material, a paint, an adhesive, a tackiness agent, or afiber-treating agent of the present invention comprises theaforementioned material (B) or (B1).

DETAILED DESCRIPTION OF THE INVENTION

In an isocyanate group terminated prepolymer aqueous dispersion (A) ofthe first embodiment of the present invention, a content of thesurfactant in the (A) is normally not more than 10% (hereinafter, unlessotherwise provided, % refers to “percent by weight”), preferably notmore than 5%, further preferably not more than 2%, based on the weightof the (a), and particularly preferably the (A) does not contain asurfactant. As the (A) contains a smaller amount of a surfactant, apolyurethane resin-applied product such as a paint in which the (A) isused possesses increased waterproofness.

The content of a surfactant can be measured by the following method.

The (A) is applied over a polypropylene plate with a size of 30×30 cm sothat a dried coating mm of the same has an average thickness of 200±30μm, and is dried at room temperature for 24 hours, and further, at 80°C. for 3 hours. A film obtained by peeling the coating film off is usedas a sample. 5 g of the foregoing sample and 150 g of methanol are putin a Soxhlet extractor, and are subjected to an extracting operation at60° C. for 6 hours. Thereafter, extracted liquid is dried and theextract thus obtained is weighed, and the content of the surfactant iscalculated by the formula shown below.Content of surfactant (%)=[(weight of extract)÷(weight of sample)]×100

A content of a solvent in the (A) is normally not more than 5,000 ppm,preferably not more than 3,000 ppm, further preferably not more than1,000 ppm, based on the weight of the (a), and particularly preferablythe (A) does not contain a solvent. It is preferable that the content ofthe solvent is smaller, since this allows the (A), a material (B) thatwill be described later, and a sheet material in which the (B) is usedto have less flammability in the manufacturing process, excellent safetyto the human body, and decreased impact on the environment.

A content of a solvent can be measured by a method according to gaschromatography.

The (A) contains the (a) of 60% to 85%, preferably 65% to 80%.

Since the (a) accounting for 60% or more increases a shearing efficiencyat the time of producing the (A), the (a) more easily becomes fineparticles, and particularly a ratio of particles having a particlediameter of 5,000 nanometers (hereinafter referred to as nm) or moredecreases. Consequently, the particles of the (a) dispersed therein orparticles of a resin (b) that will be described later seldom settle inthe (A) and the (B) that will be described later, respectively, wherebythe (A) and (B) have excellent storage stability. Further, since the (a)accounts for 60% or more, a relatively high-concentration aqueousdispersion can be obtained as the (B) in which the (A) is used, and thisis preferable since a paint, etc., made of the (B) attains a property ofdrying quickly.

Further, since the (a) accounts for 85% or less in the (A), a phasetransition at the time of producing the (A) easily occurs, wherebyemulsification thereof easily occurs.

The content of the (a) in an aqueous dispersion of the present inventionis derived in the following manner: approximately 1.80 g of a sample ofthe (A) or (B) is weighed and placed on a glass petri dish with adiameter of 9 cm, dried by an air circulating dryer at 130° C. for 90minutes, and a weight of the sample thus dried is expressed bypercentage with respect to the original weight of the sample.

Particles of the (a) in the (A) preferably have an average particlediameter of 30 nm to 500 nm, more preferably 30 nm to 300 nm.

A content of particles of the (a) having a particle diameter of not lessthan 5,000 nm in the (A) preferably is not more than 1 percent by volume(hereinafter referred to as vol %), more preferably not more than 0.2vol %, particularly preferably 0 vol %.

Since particles with a particle diameter of not less than 5,000 nm arenot more than 1 vol %, particles that settle are few, whereby theforegoing (A) and the (B) made of the (A), which will be describedlater, are imparted with particularly excellent storage stability.

The particle diameter distribution in the present invention is measuredby the following manner: 100 ml of water is put in a beaker with acapacity of 200 ml, 0.1 g of the (A) or (B) is added thereto while beingstirred by a magnetic stirrer (1,000 rpm), and after being stirred for10 minutes, the particle diameter distribution thereof is measured by alaser diffraction/scattering particle size distribution analyzer(“LA-700” model, manufactured by Horiba, Ltd.).

Isocyanate-terminated Prepolymer (a)

The (a) in the present invention includes an organic polyisocyanate (a1)and an active hydrogen atom-containing component (hereinafter referredto simply as active H component).

The active H component is composed of at least one chemical compoundselected from the group consisting of high-molecular-weight polyols(a2), low-molecular-weight polyols (a3) as required, chemical compounds(a4) containing a hydrophilic group and an active hydrogenatom-containing group (hereinafter referred to simply as active H group)in a molecule, and other active H group-containing chemical compounds(a5).

As the (a1), organic polyisocyanates that conventionally have been usedin the production of polyurethanes can be used. Examples of suchpolyisocyanates include aromatic polyisocyanates each of which has 2 to3, or more isocyanate groups and has 6 to 20 carbon atoms (except forcarbon atoms in NCO groups, this applies hereinafter) (the term “carbonatom(s)” is hereinafter abbreviated as C sometimes), aliphaticpolyisocyanates (C: 2 to 18), alicyclic polyisocyanates (C: 4 to 15),araliphatic polyisocyanates (C: 8 to 15), modified polyisocyanatesobtained by modifying the same, and combinations of two or more of thesame.

Examples of the aromatic polyisocyanates include 1,3-and/or1,4-phenylene diisocyanate, 2,4-and/or 2,6-tolylene diisocyanate (TDI),crude TDI, 4,4′-and/or 2,4′-diphenylmethane diisocyanate (MDI), crudeMDI [phosgenites of crude diaminodiphenyl methane {condensation productof formaldehyde and aromatic amine (e.g., aniline) or a mixture of thesame; or a mixture of diaminodiphenyl methane and a small amount (e.g.,5 to 20 wt %) of a polyamine having three or more functional groups},polyallyl polyisocyanate (PAPI)], 4,4′-diisocyanate biphenyl,3,3′-dimethyl-4,4′-diisocyanate biphenyl,3,3′-dimethyl-4,4′-diisocyanatodiphenylmethane, 1,5-naphthylenediisocyanate, 4,4′, 4″-triphenylmethan triisocyanate, m- orp-isocyanatophenylsulfonyl isocyanate. Examples of the aliphaticpolyisocyanates include ethylene diisocyanate, tetramethylenediisocyanate, hexamethylene diisocyanate (HDI), dodecamethylenediisocyanate, 1,6,11-undecan triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanate methylcaproate, bis(2-isocyanatoethyl) fumarate,bis(2-isocyanatoethyl)carbonate,2-isocyanatoethyl-2,6-diisocyanatohexanoate, and the like. Examples ofthe alicyclic polyisocyanates include isophorone diisocyanate (IPDI),dicyclohexilemethane-4,4′-diisocyanate (hydrogenated-MDI), cyclohexylenediisocyanate, methyl cyclohexylene diisocyanate (hydrogenated-TDI),bis(2-isocyanatoethyl)-4-cyclohexen-1,2-dicarboxylate, 2,5- and/or2,6-norbornane diisocyanate, and the like. Examples of the araliphaticpolyisocyanates include m- and/or p-xylylene diisocyanate (XDI),α,α,α′,α′-tetramethyl xylylene diisocyanate (TMXDI), and the like.Examples of the modified polyisocyanates include modified products ofthe aforementioned polyisocyanates (modified products containing anurethane group, a carbodiimide group, an arophanate group, a urea group,a biuret group, a uretdione group, a uretone-imine group, anisocyanurate group, and/or an oxazolidone group, etc.; those in which acontent of a free isocyanate group is normally 8% to 33%, preferably 10%to 30%, particularly 12% to 29%), for instance, modified MDI(urethane-modified MDI, carbodiimide-modified MDI, trihydrocarbylphosphate-modified MDI, etc.), urethane-modified TDI, biuret-modifiedHDI, isocyanurate-modified HDI, isocyanurate-modified IPDI, etc.Examples of a polyol used in the production of a urethane-modifiedpolyisocyanate [a free-isocyanate-containing prepolymer, obtained bycausing a reaction between excess polyisocyanate (TDI, MDI, etc.) and apolyol] include low-molecular-weight polyols that will be describedlater. Examples of the combinations of two or more include combinationsof modified MDI and urethane-modified TDI (isocyanate-containingprepolymer). Among these, those having two to three functional groups,TDI, MDI, HDI, IPDI, hydrogenated MDI, XDI, and TMXDI are preferred.Among these, TDI, HDI, and IPDI are particularly preferred.

Examples of the (a2) include polyester polyols (p1), polyether polyols(p2), polyolefin polyols (p3), and polymer polyols (p4), each of whichhas a hydroxyl equivalent (Mn per a hydroxyl group) of not less than400. It should be noted that hereinbefore and hereinafter “Mn” refers toa number-average molecular weight measured by gel permeationchromatography (GPC).

Examples of the (p1) include condensed-type polyesters (p11),polylactone polyols (p12), polycarbonate polyols (p13), and castoroil-based polyols (p14).

Examples of the (p2) include alkylene oxide (hereinafter abbreviated asAO) adducts of active H group-containing compounds (p21), and coupledproducts of the same (p22).

Examples of the (a3) include polyhydric alcohols (a31) and low-mole AOadducts (a32) of active H compounds, each of which has a hydroxylequivalent of not less than 30 and more than 400, and has 2 to 8 or morehydroxyl groups.

Examples of the (a31) include dihydric alcohols, for instance,aliphatic, alicyclic, and aromatic dihydric alcohols having 2 to 12 ormore carbon atoms [(di)alkylene glycols (the term “(di)alkylene glycols”refers to alkylene glycols and dialkylene glycols; hereinafter anexpression like this is used in the same way), for instance,(di)ethylene glycol, (di)propylene glycol, 1,2-, 1,3-, 2,3-, and1,4-butane diols, neopentylglycol, 3-methyl-1,5 pentanediol,1,6-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, and1,12-dodecanediol; low-molecular-weight diols having a cyclic group, forinstance, 1,4-bis(hydroxymethyl)cyclohexane, 1,4-cyclohexanediol, etc.,disclosed in, for instance, JP-B-45(1970)-1474]; polyhydric alcoholshaving 3 to 8 or more hydroxyl groups, for instance, alkane polyols(triols, for instance, trimethylol propane, glycerin, and hexane triol;high-functional polyols having 4 or more hydroxyl groups, for instance,pentaerythritol, sorbitol, xylitol, and mannitol), intramolecular orintermolecular dehydration products of the same (diglycerol,dipentaerythritol, sorbitan, etc.), saccharides (glucose, fructose,sucrose, etc.), and derivatives of the same (glucoside, for instance,α-methylglucoside); and polyols containing hydrophilic groups that willbe described later. Among the (a3), the (a31) are preferred, aliphaticdihydric alcohols are more preferred, and 1,4-butane diol (hereinafterabbreviated as BG) is particularly preferred.

Examples of the AOs used for producing the (p21) and the (a32) includeAOs having 2 to 12 or more carbon atoms, for instance, ethylene oxide(hereinafter abbreviated as EO), propylene oxide (hereinafterabbreviated as PO), 1,2-, 2,3-, or 1,3-butylene oxides, tetrahydrofuran,α-olefin oxides, styrene oxides, epihalohydrins (epichlorohydrin, etc.),and combinations of two or more of the same (random and/or block).

Examples of the active H compounds used for producing the (p2) and the(a32) include chemical compounds having 2 to 8 or more active hydrogenatoms (chemical compounds having one or two types of groups such as ahydroxyl group, an amino group, a mercapto group, etc.); for instance,polyhydric alcohols, polyhydric phenols, amines, polythiols, andmixtures of two of these. Examples of the polyhydric alcohols includethose described above. Examples of the polyphenols include monocyclicpolyhydric phenols (pyrogallol, catechol, hydroquinone, etc.), andbisphenols (bisphenol A, bisphenol F, bisphenol S, etc.).

Examples of the amines include monoamines and polyamines. Examples ofthe monoamines include ammonia; primary monoamines, such asmonohydrocarbyl having 1 to 20 carbon atoms (alkyl, cycloalkyl, aryl,aralkyl), amines (butylamine, cyclohexylamine, aniline, benzylamine,etc.); and alkanol amines (those having a hydroxyalkyl group with 2 to 4carbon atoms: monoethanolamine, diethanolamine, trieihanolamine,triisopropanolamine, etc.).

Examples of the polyamines include aliphatic polyamines having 2 to 8carbon atoms [for instance, alkylene diamines (ethylene diamine,trimethylene diamine, hexamethylene diamine, etc.), and polyalkylenepolyamines (diethylene triamine, etc.)], alicyclic polyamines having 4to 15 carbon atoms (dicyclohexylmethane diamine, isophorone diamine,etc.), araliphatic polyamines having 8 to 15 carbon atoms (xylylenediamine, etc.), aromatic polyamines having 6 to 20 carbon atoms(phenylene diamine, tolylene diamine, diethyltolylene diamine,diphenylmethane diamine, diphenylether diamine, polyphenylmethanepolyamine, etc.), and heterocyclic polyamines (piperazine,N-aminoethylpiperazine, and others disclosed in JP-B-55(1980)-21044 suchas imidazoline, pyrrolidine, piperidine, and 2-aminopyridine).

Examples of polythiols include polythiols equivalent to theabove-described polyhydric alcohols (in which at least a part of OHgroups thereof are substituted with SH groups), polythiols obtained by areaction between a compound having a glycidyl group and hydrogensulfide, etc.

The addition of AO to an active H compound can be carried out by a usualmethod, without a catalyst or in the presence of a catalyst (forinstance, an alkaline catalyst, an amine-based catalyst, an acidiccatalyst) (particularly at a latter stage in the addition of AO) under anormal pressure or an increased pressure in one or a plurality ofstages. For example, an active H compound and a catalyst are placed in apressure reactor, and AO is introduced therein while being pressurized.Examples of the catalyst include: alkaline catalysts such as hydroxidesof alkaline metals (lithium, sodium, potassium, and cesium); acids[perhalogenic acids (perchloric acid, perbromic acid, periodic acid),sulfuc acid, phosphoric acid, nitric acid, and the like, among whichperchloric acid is preferred], and salts of the same [preferably, saltsof bivalent or trivalent metals (Mg, Ca, Sr, Ba, Zn, Co, Ni, Cu, Al)]. Areaction temperature is normally 50° C. to 150° C., and a reaction timeis normally 2 to 20 hours.

In the case where two or more AOs are used in combination, the additionof the same may be block addition (the capped type, the balanced type,the active secondary type, etc.), random addition, or a combination ofthe foregoing two [capped after random addition: having ethylene oxidechains of 0 wt % to 50 wt % (preferably 5 wt % to 40 wt %) arbitrarilydistributed in a molecule, and being capped with an EO chain of 0 wt %to 30 wt % (preferably 5 wt % to 25 wt %) at a terminal of the molecularchain]. Among the AOs, EO alone, PO alone, THF (tetrahydrofuran) alone,PO and EO in combination, PO and/or EO and THF in combination arepreferred (in the combination cases, the addition of the same preferablyis random addition, block addition, and mixture of the same).

The number of added moles of AO is normally 1 to 140, preferably 1 to110, and particularly preferably 1 to 90 per one active hydrogen atom.The number of added moles of not more than 140 is preferable since inthis case a polyurethane resin obtained does not have an inconveniencesuch as being excessively soft or having a decreased strength.

After the completion of the AO addition reaction, the catalyst may beneutralized as required and be treated with an absorbent so that thecatalyst is removed for purification.

Examples of the (p21) include, for instance, polyoxyethylene polyol[polyethylene glycol (hereinafter abbreviated as PEG), etc.],polyoxypropylene polyol [polypropylene glycol (hereinafter abbreviatedas PPG), etc.], polyoxyethylene/propylene polyol, polytetramethyleneether glycol, and EO and/or PO adducts of bisphenols.

Examples of the (p22) include those obtained by coupling two or moremolecules of the (p21) by using alkylene halide (C: 1 to 6, forinstance, methylene dichloride).

The (p2) desirably has a smaller unsaturation degree (not more than 0.1meq/g, preferably not more than 0.05 meq/g, particularly preferably notmore than 0.02 meq/g), and desirably contains primary hydroxyl groupsthat account for at least 30%, preferably at least 50%, particularlypreferably at least 70% of all the hydroxyl groups therein.

Examples of the (p 11) include polycondensation products obtained bycondensation polymerization of a polyol and a polycarboxylic acid (c1),examples of the (p12) include polyaddition products obtained bypolyaddition of lactone (c2) to a polyol, examples of the (p13) includepolyaddition products obtained by polyaddition of a alkylene carbonate(c3) to a polyol, and examples of the (p14) include castor oil, andcastor oil modified with a polyol or AO.

Examples of the polyols used for forming those above-described include(a3) and/or (p2) [preferably those having a hydroxyl equivalent of notmore than 500].

Examples of the (c1) include aliphatic, alicyclic, or aromaticcarboxylic acids having a valence of 2 to 8 or more and 4 to 40 or morecarbon atoms, which include dicarboxylic acids such as aliphaticdicarboxylic acids (succinic acid, adipic acid, azelaic acid, sebacicacid, fumaric acid, maleic acid, etc.), alicyclic dicarboxylic acids(dimeric acid, etc.), aromatic dicarboxylic acids (terephthalic acid,isophthalic acid, phthalic acid, etc.), and polycarboxylic acids havinga valence of 3 or more (trimellitic acid, pyromellitic acid, etc.).Among these, it is preferable to use the dicarboxylic acid, and acombination of the dicarboxylic acid and a small amount (not more than20%) of the polycarboxylic acid having a valence of 3 or more.

Examples of the (c2) include lactones having 4 to 12 carbon atoms suchas 4-butanolide, 5-pentanolide, and 6-hexanolide. Examples of the (c3)include alkylene (C: 2 to 8) carbonate such as ethylene carbonate andpropylene carbonate. These may be used in combination of two or more.

The (p1) can be produced by a normal method. The (p11) can be producedby, for instance, a dehydration condensation polymerization ortransesterification of the (c1) or an ester-forming derivative of thesame [an anhydride of an acid (maleic anhydride, phthalic anhydride,etc.), lower alkyl (C: 1 to 4) esters (dimethyl adipate, dimethylterephthalate, etc.), an acid halide (acid chloride, etc.)] with apolyol in an excess equivalent amount, or by dehydrating condensationpolymerization or transesterification of the (c1) or an ester-formingderivative of the same with a polyol followed by a reaction with AO, oralternatively, by a reaction of a polyol with an acid anhydride and AO.The (p12) and the (p13) can be produced by polyaddition of the (c2) or(c3) using a polyol as an initiator. The modified castor oil can beproduced by transesterification of the castor oil with a polyol and/orAO addition of the same.

Examples of the (p11) include polyethylene adipate diol, polybutyleneadipate diol [for instance, “SANESTER 4620” (Mn=2,000) produced by SanyoChemical Industries Co., Ltd., hereinafter abbreviated as PES],polyhexamethylene adipate diol, polyneopentyl adipate diol, polyethylenepropylene adipate diol, polyethylene butylene adipate diol, polybutylenehexamethylene adipate diol, polydiethylene adipate diol,poly(polytetramethylene ether) adipate diol, poly(3-methylpentyleneadipate) diol, polyethylene azelate diol, polyethylene sebacate diol,polybutylene azelate diol, polybutylene sebacate diol, and polyneopentylterephthalate diol. Examples of the (p12) include polycaprolactone diol,polyvalerolactone diol, and polycaprolactone triol. Examples of the(p13) include polyhexamethylene carbonate diol [for instance, “Nipporan980R” (Mn=2,000) produced by Nippon Polyurethane Industry Co., Ltd.,hereinafter abbreviated as PC]. Examples of the (p 14) include castoroil, trimethylol propane-modified castor oil, pentaerythritol-modifiedcastor oil, EO (4 to 30 moles) adducts of castor oil.

Examples of the (p3) include: polyalkadiene-based polyols, such aspolybutadiene diol [diol of polybutadiene having a 1,2-vinyl structureand/or a 1,4-trans structure (butadiene homopolymer, and copolymer suchas styrene butadiene copolymer, acrylonitrile butadiene copolymer)], andhydrogenation products of the same (hydrogenation ratio: for instance,20% to 100%); and acryl-base polyols, such as copolymers of hydroxyalkyl(C: 2 to 6) (meth)acrylate [ethyl hydroxyethyl (meth)acrylate, etc.] andother monomers [styrene, alkyl (C: 1 to 18) (meth)acrylate, etc.]. Here,it should be noted that “(meth)acryl . . . ” refers to “acryl . . . ” or“methacryl . . . ”. Examples of the polybutadiene diol include“NISSO-PBG” series (e.g., “G-1000”, “G-2000”, “G-3000”, etc.) producedby Nippon Soda Co., Ltd., and “Poly Bd” (e.g., “R-45M”, “R-45HT”,“CS-15”, “CN-15”, etc.) produced by ARCO chemical Co. in the US.

Examples of the (p4) include polymer-containing polyols that areobtained by polymerizing a radical-polymerizable monomers in situ in apolyol [the above-described (p1) and/or the (p2), and the (a3) asrequired]. Examples of the monomer include styrene, (meth)acrylonitrile,(meth)acrylate, vinyl chloride, and mixtures of two or more of the same.The polymerization of a monomer is performed normally in the presence ofa polymerization initiator. Examples of the polymerization initiatorinclude those that initiate polymerization by generating free radicals,for instance, azo compounds such as 2,2′-azobisisobutyronitrile (AIBN)and 2,2′-azobis-(2,4-dimethylvaleronitrile) (AVN); dibenzoyl peroxide,dicumyl peroxide, peroxides other than those described above, disclosedin JP-A-61(1986)-76517 (for instance, lauroyl peroxide, di-t-butylperoxide, butyl isobutyl peroxide), salts of persulfurc acid, salts ofperboric acid, and persuccinic acid. The azo compounds, particularlyAIBN and AVN, are preferred. The amount of the polymerization initiatorto be used is normally 0.1% to 20%, preferably 0.2% to 10% based on thetotal amount of monomer. The polymerization in a polyol can be performedwithout a solvent, but in the case where the concentration of thepolymer is high, the polymerization is performed preferably in thepresence of an organic solvent. Examples of the organic solvent includebenzene, toluene, xylene, acetonitrile, ethyl acetate, hexane, heptane,dioxane, N,N-dimethyl-formamide, N,N-dimethyl acetamide, isopropylalcohol, and n-butanol. The polymerization may be performed in thepresence of a chain transfer agent (alkylmercaptans, carbontetrachloride, carbon tetrabromide, chloroform, enol ethers, etc.) asneeded. The polymerization may be performed at a temperature at orhigher than a decomposition temperature of the polymerization initiator,normally 60° C. to 180° C., preferably 90° C. to 160° C., and under anatmospheric pressure, an increased pressure, or a reduced pressure.After the completion of the polymerization reaction, the polymer polyolobtained can be used in the as-is state for forming a polyurethane, butit is desirable that after the completion of the reaction, impuritiessuch as an organic solvent, decomposition products of a polymerizationinitiator, and non-reacted monomers are removed by a conventional means.

The (p4) is a semi-transparent or opaque, white or yellowish dispersion,which is a polyol in which a polymerized monomer, that is, a polymer, ofnormally 30% to 70% (preferably 40% to 60%, particularly preferably 50%to 55%) is dispersed. The hydroxyl value of the (p4) is normally 10 to300, preferably 20 to 250, particularly preferably 30 to 200.

Among the (a2), the (p1) and the (p2) are preferred, among which the(p1) is further preferred. Among these, the (p11) and the (p13) areparticularly preferred.

The (a2) normally has a hydroxyl equivalent of 400 to 3,000, preferably400 to 2,000, particularly preferably 500 to 1,700. In the case wherethe hydroxyl equivalent thereof is 400 to 5,000, a polyurethane resinproduced using the same will have excellent flexibility.

The (a2) normally has an average number of functional groups of 2 to 3,preferably 2.3 to 3, and more preferably 2.4 to 2.9. In the case wherethe average number of functional groups thereof is 2 to 3, apolyurethane resin produced using the same will have excellentflexibility, and excellent solvent resistance.

The (a2) normally has a Mn of 800 to 9,000, and preferably 1,000 to4,000.

The (a2) may be used without the (a3), or may be used along with the(a3) in combination, but in the case where the (a3) is used incombination, it is preferable to use the (a3) in a small amount (forinstance, not more than 20%), considering the properties of apolyurethane resin.

As the active H component to be used in the reaction with the (a1), thecompound (a4) containing a hydrophilic group and an active H group inits molecule may be used additionally. By so doing, an aqueousdispersion of an autoemulsifying-type (a) can be obtained. Theautoemulsilying-type (a) is preferable as compared with the (a) withoutthe use of the (a4), which is emulsified by an emulsifier, since theautoemulsifying-type (a) does not require an emulsifier or requires onlya small amount of the same to be used, whereby in the case where thematerial obtained is used for forming a paint or a sheet material to bedescribed later, the paint or the sheet material is allowed to haveexcellent waterproofness.

Examples of the hydrophilic group in the (a4) include anionic groups(sulfonic acid group, sulfamic acid group, phosphoric acid group,carboxyl group, etc., and salts of the same), cationic groups(quaternary ammonium groups, primary to tertiary amino groups, and saltsof the same), and nonionic groups (an oxyethylene group, a hydroxylgroup, etc.).

Examples of the (a4) include compounds containing 1, or 2 to 8, or moreactive H groups, and examples of the active H group include a hydroxylgroup and an amino group. Compounds having two or more (particular two)active H groups, and combinations of the same with compounds having oneactive H group are preferred (the ratio by weight of the two incombination is 100/0 to 50/50).

Examples of the compounds having an anionic group and an active H group(a41) include:

-   (a411) compounds having a sulfonic acid group and an active H group:    -   diol sulfates [3-(2,3-dihydroxypropoxy)-1-propane sulfonic acid        (hereinafter abbreviated as DHS), di(ethylene glycol)        sulfoisophthalate, etc.], and aminosulfonic acids [2-aminoethane        sulfonic acid, 3-aminopropane sulfonic acid, etc.],-   (a412) compounds having a sulfamic acid group and an active H group:    -   diol sulfamates [N,N-bis(2-hydroxyalkyl) sulfamate (C in an        alkyl group: 1 to 6) or AO adducts of the same (EO or PO, etc.,        is used as AO, the number of added moles of AO:1 to 6): for        instance, N,N-bis(2-hydroxyethyl) sulfamic acid, PO (2 moles)        adduct of N,N-bis(2-hydroxyethyl) sulfamic acid, etc.],-   (a413) compounds having a carboxyl group and an active H group:    -   dialkylol alkanoic acids [C: 6 to 24, for instance,        2,2-dimethylol propionic acid (hereinafter abbreviated as DMPA),        2,2-dimethylol butanoic acid, 2,2-dimethylol heptanoic acid,        2,2-dimethylol octanoic acid, etc.],-   (a414) compounds having another anionic group and an active H group:    -   bis(2-hydroxyethyl) phosphate, amino acids (2-amino ethane acid,        etc.), and    -   salts of the same, such as salts of the same with tertiary        amines [trialkylamines having an alkyl group with 1 to 18 carbon        atoms [trimethylamine, triethylamine (hereinafter abbreviated as        TEA), dimethylethylamine, diethyloctylamine, etc.], and        alkanolamine], salts of the same with morpholine, and/or salts        of the same with alkali metals (salts of the same with sodium,        potassium, lithium, etc.).

Examples of the compounds (a42) having a cationic group and an active Hgroup include diols containing a quaternary ammonium salt group, diolscontaining a tertiary amino group, and salts of the same (salts ofcarboxylic acid, etc.), examples of which include: alkyl (C: 1 to 8)dialkanol (C: 2 to 4) amine (e.g., N-methyldiethanolamine), dialkyl (C:1 to 6) alkanol (C: 2 to 4) amine (e.g., N,N-dimethylethanolamine), andneutralized products obtained by neutralization with acids of theforegoing compounds [organic acids such as carboxylic acids having 1 to8 carbon atoms (acetic acid, propionic acid, lactic acid, octanoic acid,etc.), sulfonic acids (toluenesulfonic acid, etc.); inorganic acids suchas hydrochloric acid, sulfonic acid, phosphoric acid, etc.], andcompounds quaternized by a quaternization agent [ester of sulfonic acid,ester of carboxylic acid, halides (dimethyl sulfate, dimethyl carbonate,methyl chloride, benzyl chloride, etc.) having an alkyl group or abenzyl group (C: 1 to 8), etc.].

Examples of the (a4) having a nonionic group as a hydrophilic groupinclude PEG, polyethylene propylene glycol (Mn=100 to 3,000), and thelike.

The nonionic (a4) and the anionic (a41) or cationic (a42) may be used incombination.

Among the (a4), the (a41) and the (a42) are preferred, among which the(a41), particularly the (a411) and (a413) and the combination of thesame is further preferred. Diol sulfonate, sodium salt of dialkylolalkanic acid, or salts of tertiary amines are particularly preferred.

The content of the (a4) in an autoemulsifying-type (a) aqueousdispersion is preferably not less than 0.1% based on a weight of the(a), more preferably 0.5% to 30%. Particularly, in the case where the(a4) is a nonionic compound, the content is preferably 3% to 30% [in thecase where the (p1) or the (p2) is used and a polyoxyethylene chain (thenumber of added moles: not less than 2) is contained therein, the weightof the same is included], more preferably 5% to 20%.

Further, in the case where the (a4) is an ionic compound, the content ofthe ionic group based on the weight of (a) (except for counter ions) ispreferably 0.01% to 10%, more preferably 0.1% to 8%, particularlypreferably 0.2% to 5%, which are, if converted into an equivalent,preferably 0.002 milli-equivalent per gram (hereinafter referred to as“milli-equivalent/g”) to 2 milli-equivalent/g, more preferably 0.02milli-equivalent/g to 1.8 milli-equivalent/g, particularly preferably0.04 milli-equivalent/g to 1 milli-equivalent/g.

Particularly, in the case where the (a413) and/or the (a411) is used asthe (a4), the ratio of —COO^(—)and/or —SO₃ ^(—)based on the weight ofthe (a) is preferably 0.01% to 8%, more preferably 0.2% to 5%.

As the active H component used in the reaction with the (a1), theanother active H compound (a5), which is other than the (a2) to (a4),can be used as required. Examples of the (a5) include active Hpolyfunctional compounds (a51) and monofunctional compounds (a52).Examples of the (a51) include the above-described polyamines, andpolyether polyamines [hydrides of cyanoalkylated (C: 2 to 4) compounds(cyanated-ethylated compounds, etc.) of the (p2) and/or the (a32)].Examples of the (a52) include the above-described primary monoamines andsecondary monoamines such as di-hydrocarbyl (alkyl, cycloalkyl, aryl,and/or aralkyl (C: 1 to 20)) amines (such as dibutyl amine) and AOadducts of the same, monohydric alcohols (alkanol (C: 1 to 20),cyclohexanol, benzyl alcohol, etc.) and AO adducts of the same.

In the production of the (a), the order of the reactions of theforegoing components is not particularly limited, and examples of theproduction method include a method in which the (a1) and all the activeH components are caused to react simultaneously, and a method in whichafter the (a1) and the (a2), as well as the (a3) as required, are causedto react simultaneously, the (a4) is caused to react with the same asrequired. The reaction temperature is normally 30° C. to 100° C.,preferably 40° C. to 80° C.

Further, in the production process of the (a), it is preferable to useno solvent.

The amount of a solvent that is allowed to be mixed therein is normallynot more than 5,000 ppm based on the weight of the (a), preferably notmore than 2,000 ppm, and further preferably no solvent is contained,taking the flammability, and the safety to the human body and theenvironment into consideration. Examples of a solvent allowed to becontained therein include hydrophilic organic solvents that aresubstantially non-reactive with an isocyanate group, such asketone-based solvents (acetone, methyl ethyl ketone, etc.), N-methylpyrrolidone (hereinafter abbreviated as NMP), dimethyl formamide,tetrahydrofuran, and dioxane.

The equivalent ratio of NCO group/active hydrogen for reaction ispreferably 1.3 to 2.2, and more preferably 1.4 to 2.0. In the case wherethe equivalent ratio is not less than 1.3, the (a) does not have anexcessively high molecular weight, and hence, does not have a highviscosity. Further, in the case where the equivalent ratio is not morethan 2.2, non-reacted isocyanate groups in the (a) decreases, which ispreferable from the viewpoint of stability.

Further, the content of non-reacted isocyanate groups in the (a)produced is normally 0.5% to 10%, preferably 1.5% to 6%.

Still further, the (a) has a viscosity at 60° C. of, preferably, 20 Pa·sto 1,000 Pa·s, further preferably 20 Pa·s to 800 Pa·s. In the case wherethe viscosity at 60° C. is 20 Pa·s to 1,000 Pa·s, the mixing of the (a)and water in a continuous mixer that will be described later is eased.

It should be noted that the viscosity of the (a) is measured by aBH-type viscometer, and a viscosity of the (A) or (B) that will bedescribed later is measured by a BL-type viscometer (60 rpm).

Isocyanate Group Terminated Prepolymer Aaqueous Dispersion (A)

The (A) of the present invention is obtained by subjecting theabove-described (a) and water to contact mixing (with use of anemulsifier as required) so that the (a) is emulsified and dispersed.

Since the (a) of the present invention has a high viscosity, a kneaderused for producing the (A) has an operation power of, preferably, notless than 20 KW/m³, more preferably not less than 500 KW/m³,particularly preferably not less than 2,000 KW/m³. A kneader thatexhibits an operation power of less than 20 KW/m³ either is completelyincapable of kneading the (a) or often stops in midstream of thekneading operation. The kneading temperature is normally 20° C. to 80°C., preferably 30° C. to 70° C., and the viscosity of the (a) at atemperature in the foregoing range is preferably 20 Pa·s to 10,000 Pa·s,more preferably 50 Pa·s to 2,000 Pa·s, particularly preferably 100 Pa·sto 1,000 Pa·s.

The operation power is defined as a value obtained by subtracting avalue of a driving power during a no-load operation from a value of adriving power during a kneading operation (normally derived from acurrent value and a voltage during an operation) and dividing thesubtraction result by a capacity of the kneader. With the use of akneader that can exhibit an operation power of not less than 20 KW/m³, ahigh-concentration aqueous dispersion is produced easily, and ispulverized finely. The kneader may be a batch type or a continuous type,but from the viewpoint of productivity, the continuous-type kneader ispreferred.

Examples of a continuous kneading machine that can exhibit an operationpower of not less than 20 KW/m³ include the following fixed-containerhorizontal-axis-type continuous kneading machines, described in “KongoKonren Gijutsu (Mixing and Kneading Technologies)” edited by TheAssociation of Powder Process Industry and Engineering, published by TheNikkan Kogyo Shimbun, Ltd., Apr. 30, 1987, 250 pages, or “Konren Sochi(Kneading Machines)” written by Kenjiro HASHIMOTO, edited by KagakuGijutsu Sogo Kenkyusho (Research Institute for Science and Technology),Sep. 20, 1989, 224 pages.

-   (i) continuous kneader (“KRC kneaders” manufactured by Kurimoto,    Ltd.);-   (ii) taper roll (manufactured by Hitachi, Ltd.);-   (iii) extruder (manufactured by Ikegai, Ltd., Toshiba Machine Co.,    Ltd.);-   (iv) single-axis screw extruder (manufactured by Hosokawa Iron Works    (currently, Hosokawa Micron Corporation));-   (v) “Ko-kneader”-type screw extruder (manufactured by Yashima Bussan    Co., Ltd.)-   (vi) votator-type kneader (manufactured by Sakura Seisakusho, Ltd.)

These kneaders radiate less heat at the time of kneading, and do notadversely affect the aqueous dispersion. Considering this point, theseare more preferable as compared with a rotor/stator dispersing machine,etc., used in the production of the (B) that will be described later.

Among these, the (i) and (ii) are further preferred, which aremultiaxial with two or three axes and are excellent in self-cleaning.

Examples of the process of contact mixing include a process (1) in whichthe (a) is fed to a continuous kneader with a pump, and water or anaqueous solution of an emulsifier is fed continuously or intermittentlyto a midpoint of a path of the kneader by using a pump, so that contactmixing is achieved, and a process (2) in which water or an aqueoussolution of an emulsifier is fed to a continuous kneader by using apump, and the (a) is fed to a midpoint of a path of the kneader by usinga pump, so that contact mixing is achieved. The process (1) ispreferred.

The temperature of the (a) fed to the kneader is preferably 40° C. to100° C., and more preferably 50° C. to 90° C. At a temperature of notlower than 40° C., the (a) does not have an excessively high viscosity,whereby the emulsifying dispersion is facilitated. On the other hand, ata temperature of not higher than 100° C., the stability of the (a)hardly deteriorates.

Further, the temperature of water or the aqueous solution of anemulsifier is preferably 10° C. to 50° C., and more preferably 20° C. to40° C. At a temperature of not lower than 10° C., the contact mixing isfacilitated. On the other hand, at a temperature of not higher than 40°C., a chain extension reaction due to water is not accelerated. Withthis, in a subsequent process of the production of a polyurethane resinaqueous dispersion (B), deviation from a molar ratio of an amine used inthe chain extension reaction is suppressed, whereby a (B) with excellentproperties can be obtained more easily.

The time of dispersion in a continuous kneader (a residence time in thekneader) is normally 1 to 300 seconds, and preferably 3 to 100 seconds.In the case of 1 to 300 seconds, a stable dispersion is obtained. Theflow rate of the sum of the (a) and water passing through the kneader isnormally 10 L/hr to 4,000 L/hr, preferably 20 L/hr to 3,000 L/hr.

The amount of an emulsifier used is preferably not more than 10% basedon the weight of the (a), more preferably not more than 5%, further morepreferably not more than 2%. Particularly preferably, no emulsifier isused. It is preferable that the emulsifier is not used, since in thiscase, paints, adhesives, and the like obtained from the polyurethaneresin aqueous dispersion (B) tend to have excellent waterproofness andphysical properties.

Examples of the emulsifier include anionic, cationic, nonionic, andamphoteric surfactants, polymer-type emulsifiers, and combinations oftwo or more of the same, for instance, those described in U.S. Pat. No.3,929,678 and U.S. Pat. No. 4,331,447.

Examples of the anionic surfactant include the following surfactantshaving hydrocarbon groups having 8 to 24 carbon atoms:

ether carboxylic acids and salts of the same [sodium lauryl etheracetate, sodium (poly)oxyethylene lauryl ether acetate, etc.];

sulfic esters or ether sulfuric esters, and salts of the same [sodiumlauryl sulfate, sodium (poly)oxyethylene lauryl sulfate, triethanolamine(poly)oxyethylene lauryl sulfate, sodium (poly)oxyethylene coconut oilfatty acid monoethanol amide sulfate, etc.];

salts of sulfonic acid [sodium dodecylbenzene sulfonate, etc.];

salts of sulfosuccinic acid, phosphoric ester or ether phosphoric ester,and salts of the same [sodium lauryl phosphate, sodium (poly)oxyethylenelauryl ether phosphate, etc.];

salts of fatty acids [sodium laurate, triethanolamine laurate, etc.];and

salts of acylated amino acids [sodium coconut oil fatty acidmethyltauride, sodium coconut oil fatty acid sarcoside, triethanolaminecoconut oil fatty acid sarcoside, triethanolamine N-coconut oil fattyacid acyl-L-glutamate, sodium N-coconut oil acid acyl-L-glutamate,sodium lauroyl methyl-β-alanide, etc.].

Examples of the nonionic surfactants include:

AO adducts of aliphatic alcohols (C: 8 to 24) [polyoxyethylene (thenumber of added moles of EO:18) cetyl ether, polyoxyethylene (the numberof added moles of EO:11) lauryl ether, etc.];

polyhydric alcohol fatty acid (C: 8 to 24) esters [glycerolmonostearate, sorbitan monolaurate, etc.];

aliphatic acid (C: 8 to 24) alkanolamide [1:1-type coconut oil fattyacid diethanolamide, 1:1-type lauric acid diethanolamide, etc.];

(poly)oxyalkylene alkyl (C: 1 to 22) phenyl ethers;

(poly)oxyalkylene (C: 2 to 8) alkyl (C: 8 to 24) amines; and

alkyl (C: 8 to 24) dialkyl (C: 1 to 6) amine oxide [lauryl dimethylamine oxide, etc.].

The nonionic surfactant preferably has a HLB of 8 to 20, morepreferably, 10 to 18. The HLB in the present invention is a valuederived from the Griffin equation shown below, which is described in“Shin Kaimen Kasseizai Nyumon (New Surfactant Primer) written byTakehiko FUJIMOTO, published by Sanyo Chemical Industries Co., Ltd.,1992, page 128:HLB=(wt % of hydrophilic group)×(1/5)

Examples of the cationic surfactant include: quaternary ammoniumsalt-type [stearyl trimethyl ammonium chloride, behenyl trimethylammonium chloride, distearyl dimethyl ammonium chloride, lanolin fattyacid aminopropyl ethyl dimethyl ammonium ethylsulfate, etc.], and aminesalt-type [salt of diethyl aminoethylamide lactic acid stearate, salt ofdilaurylamine hydrochloric acid, salt of oleylamine lactic acid, etc.].Examples of the amphoteric surfactant include betaine-type amphotericsurfactants [betaine coconut oil fatty acid amide propyl dimethylaminoacetate, betaine lauryl dimethylamino acetate, betaine2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinide, laurylhydroxysulfobetaine, sodium lauroylamide ethyl hydroxyethylcarboxymethyl betaine hydroxypropyl phosphate, etc.], and aminoacid-type amphoteric surfactants [sodium P-lauryl aminopropionate,etc.].

As the polymer emulsifier, the following can be used: polyvinyl alcohol,starch, and derivatives of the same; cellulose derivatives such ascarboxymethyl cellulose, methyl cellulose, and hydroxyethyl cellulose;carboxyl group-containing (co)polymers, such as sodium polyacrylate,having Mn of 1,000 to 50,000; and polymer-type emulsifiers having aurethane bond or an ester bond described in the specification of U.S.Pat. No. 5,906,704 [e.g., polycaprolactone polyol (p12) and polyetherdiol (p2) bonded by polyisocyanate (a1)]. The Mn of these polymer-typeemulsifiers is normally 3,000 to 1,000,000, preferably 5,000 to 100,000.

In the case where an emulsifier is used, the nonionic surfactants, theanionic surfactants, and combinations of the same are preferred from theviewpoint of the emulsification dispersion stability of an aqueousdispersion, among which the nonionic surfactants further are preferred.

Polyurethane Resin Aqueous Dispersion (B)

The (B) according to another embodiment of the present invention isobtained by a chain extension reaction of the (A). Examples of anapplicable chain extender (E) include aqueous liquids of polyamine (E1)[an aqueous liquid containing an aqueous solution, or water and theabove-described aqueous solvent, in a range of not more than 5,000 ppmbased on the weight of the (a), among which the aqueous solution ispreferred], and water.

Examples of the (E1) include:

aliphatic polyamines (E11) [aliphatic diamine; alkylene diamine (C: 2 to18) such as ethylene diamine (EDA), tetramethylene diamine, andhexamethylene diamine, as well as polyalkylene (C: 2 to 6) polyamine(having 3 to 25 amino groups) and alkyl (C: 1 to 8)-substitutedderivatives of the same, such as diethylene triamine, triethylenetetramine, and tetraethylene pentamine],

alicyclic polyamines (E12) [4,4′-diaminodicyclohexyl methane,1,4-diaminocyclohexane, isophorone diamine (IPDA), etc.]

aliphatic polyamines having an aromatic ring (E13) [xylylene diamine,tetramethyl xylylene diamine, etc.],

aromatic polyamines (E14) [4,4′-diaminodiphenyl methane, tolylenediamine, diethyl tolylene diamine, etc.],

heterocyclic polyamines (E15) [piperazine, aminoethyl piperazine, etc.],

alkanol amines (E16) [monoethanol amine, diethanolamine,2-amino-2-methyl propanol, etc.],

hydrazines (hereinafter abbreviated as HDH) and hydrazine derivatives(E17) [carbodihydrazide, adipic acid dihydrazide, etc.].

Among those listed as the (E), the aqueous liquids of the (E1) arepreferred considering their high rate of reaction, among which the(E11), (E12), (E17), and combinations of two or more of the same furtherare preferred considering the ease of control of the molecular weight ofa polyurethane resin to be produced.

The equivalent ratio of the sum of the primary and secondary aminogroups of the (E1), i.e., (NH₂+NH) with respect to the isocyanate groupsof the (a), i.e., [(NH₂+NH)/NCO] is normally 0.2 to 0.9, and preferably0.3 to 0.8. In the case where the ratio is not less than 0.2, carbonacid gas is generated mildly in the chain extension reaction process,whereby particles of a polyurethane resin tend to be made finer. In thecase where the ratio is not more than 0.9, the molecular weight controlof a polyurethane resin to be produced is facilitated.

The concentration of the (E1) in the case where an aqueous liquid of the(E1) is used is preferably 0.5% to 20%, more preferably 0.5% to 10%.

In the case where a terminating agent is used, monohydric alcohols(methanol, isopropanol, and butanol, etc.) having 1 to 6 carbon atoms,the above-described monoamines, or the like may be used, and in thiscase, the equivalent ratio of the terminating agent is 0.02 to 0.2 withrespect to NCO.

The production of the (B) in the present invention can be achieved bymixing the (A) and the (E) which causes a chain extension reaction ofthe (A).

The operation power of a mixing dispersing machine that can be used formixing the (A) and the (E) is not particularly limited. The followingmixing dispersing machines can be used:

(i) rotor/stator dispersing machine: (“Ebara Milder MDN-303V”manufactured by Ebara Corporation, “CAVITRON CD-1010” manufactured byNittetsu Mining Co., Ltd., “KORUMA DISYO 60” manufactured by Fuji GokinTekko KYK., “SUPER-DISPAX SD41” manufactured by IKA WORKS, INC., etc.);

(ii) ultrasonic vibration dispersing machine (“Ultrasonic HomogenizerRUS-600” manufactured by Nihon Seiki Seisakusho K.W, “T.K. MicromizerUJ-20” manufactured by Thkushu Kika Kogyo Co., Ltd., etc.);

(iii) high-pressure impact dispersing machine (“Gauhin Homogenizer 15Mmodel” manufactured by Mount Gaulin Laboratory Co., “Microfluidizer M110ET model” manufactured by Mizuho Industrial Co., Ltd., “T. K. Nanomizer”manufactured by Thkushu Kika Kogyo Co., Ltd., etc.); and

(iv) vibration dispersing machine (“VIBRO MIXER” manufactured by REIKACo., etc.)

Among these dispersing machines, the (i) and (iv) are preferred forcontinuous production, among which the (i) is particular preferred sinceit is scaled up easily.

The method for mixing and dispersing the (A) and (E) of the presentinvention is not particularly limited, and examples of the methodinclude:

(1) feeding the (A) to a dispersing machine, and feeding the (E) to amidpoint of a path of the dispersing machine by using a pump so thatthey are mixed,

(2) bringing the (A) and (E) into contact at an inlet of a dispersingmachine and feeding the same into the dispersing machine so that theyare mixed, and

(3) feeding the (E) to a dispersing machine by using a pump, and feedingthe (A) to a midpoint of a path of the dispersing machine so that theyare mixed.

Among these, the methods (1) and (2) are preferred.

The conditions under which the (A) and (E) are mixed are as follows, inthe case where, for instance, the method (1) is applied: the number ofrevolutions of the dispersing machine is preferably 2,000 rpm to 14,000rpm, more preferably 3,000 rpm to 12,000 rpm. The time of dispersion(residence time) is preferably 0.5 to 30 seconds, more preferably 3 to20 seconds. The flow rate of a liquid in a dispersing machine ispreferably 10 L/hr to 6,000 L/hr, more preferably 20 L/hr to 4,000 L/hr.

Further, the temperature of the (E) is normally 10° C. to 60° C.,preferably 20° C. to 50° C. The viscosity of the (B) (at 25° C.) ispreferably 0.01 Pa·s to 3 Pa·s.

The content of the surfactant in the (B) is normally not more than 10%,preferably not more than 5%, and more preferably not more than 2% basedon the weight of the (a), and it is particularly preferable that nosurfactant is contained. It should be noted that the limitation on thecontent of a surfactant in the foregoing range applies also to thecontent thereof based on the weight of the (b). A smaller content of asurfactant is preferable since better waterproofiiess is imparted to apaint or the like in which the (B) is used. The surfactant content canbe measured by the same method as that for the (A).

The content of a solvent in the (B) is normally not more than 5,000 ppm,preferably not more than 3,000 ppm, more preferably not more than 1,000ppm based on the weight of the (a), and it is particularly preferablethat no solvent is contained. It should be noted that the content of asolvent in the (B) based on the weight of the (b) is in substantiallythe same range as the above range. With a smaller content of a solvent,the (B) and a sheet material or the like in which the (B) is usedexhibit less flammability at the time of production, excellent safety tothe human body, and smaller impact on the environment. The solventcontent can be measured by the same method as the above method in thecase of the (A).

The (B) contains the (b), the content of the (b) being in a range of 20%to 65%, preferably in a range of 40% to 60%.

It is preferable that the content of the (b) is not less than 20%, sincein this case a paint or the like obtained from the (B) is imparted witha high drying rate.

The average particle diameter of the (b) in the (B) is substantially thesame as the particle diameter of the (a), and the (b) preferably has anaverage particle diameter of 30 nm to 500 nm, more preferably 30 nm to300 nm. A content of particles of the (b) having a particle diameter ofnot less than 5,000 nm in the (B) preferably is not more than 1 vol %,more preferably not more than 0.3 vol %. This is preferred sinceparticles with a particle diameter of not less than 5,000 nm are notmore than 1 percent, particles that settle are few, whereby the (B) areimparted with excellent storage stability.

The (B) of the present invention is applicable for the use in paints,coating materials, adhesives, tackiness agents, fiber-treating agents,and sheet materials that will be described below.

Paints, Coating Materials

The (B) of the present invention can be used as a binder component in apaint (a coating material), and is used normally in an aqueous paint.

A crosslinking agent can be contained in a paint with a view toimproving properties of a paint film. Examples of the crosslinking agentinclude the following (x1) to (x4):

(x1) watersoluble or water-dispersible amino resins such as melamineresins containing an (alkoxy)methylol group and/or an imino group, andurea resins having the same groups [melamine resins having a methylolgroup and/or an imino group are preferred];

(x2) water-soluble or water-dispersible polyepoxides, such as glycidylethers such as bisphenol A glycidyl ether, hydrogenated bisphenol Aglycidyl ether, and glycidyl ethers of polyols [the above-described(a31) (ethylene glycol, glycerin, trimethylol propane, sorbitol, etc.),and AO (C: 2 to 3) adducts of the same (PEG, etc.)], and polyepoxidesimparted with water-dispersibility by adding an emulsifier (such as theaforementioned surfactants, etc.) thereto, and the like [glycidyl ethersof polyhydric alcohols are preferred, among which sorbitol poly(di tohexa)glycidyl ethers and glycerin poly(di or tri)glycidyl ethers areparticularly preferred];

(x3) water-soluble or water-dispersible polyisocyanate compounds such aspolyisocyanates having a hydrophilic group (a polyoxyethylene chain,etc.) in each molecule [“CORONATE 3062” and “CORONATE 3725”(manufactured by Nippon Polyurethane Industry Co., Ltd.), etc.], andblocked polyisocyanates [the above-described (a1) (isocyanurate-modifiedIPDI, etc.) blocked by using blocking agents (phenols disclosed in thespecification of U.S. Pat. No. 4,524,104, active methylene compounds,lactam, oxime, bisulfite, tertiary alcohols, aromatic secondary amines,imides, or mercaptans such as phenol, methyl ethyl ketone (MEK),εcaprolactone, etc.)]; and

(x4) polyethylene ureas (diphenylmethane-bis-4,4′-N,N′-ethylene urea,etc.), and the like.

The amount of a crosslinking agent to be added is normally 0% to 30%,preferably 0.1% to 20%, based on a weight of the (b) in the (B).

In the case of a paint, other additives may be added as required. Forinstance, one or two, or more of pigments, pigment dispersers, viscosityregulators, antifoaming agents, leveling agents, preservatives,deterioration inhibitors, stabilizers, and freezing inhibitors may beadded.

Examples of the pigments include:

inorganic pigments such as white pigments (titanium white, hydrozincite,lithopone, white lead, etc.), transparent white pigments (calciumcarbonate, barium sulfate, calcium silicate, etc.), black pigments(carbon black, animal black, red lead, etc.), grey pigments (zinc dust,slate powder, etc.), red pigments (red iron oxide, red lead, etc.),brown pigments (amber, iron oxide powder, Vandyke brown, etc.), yellowpigments (chrome yellow, zinc chromate, yellow iron oxide, etc.), greenpigments (chromium green, chromium oxide, viridian, etc.), blue pigments(ultramarine blue, iron blue, etc.), violet pigments (Mars violet,cobalt violet light, etc.), metallic pigments (aluminum flake, copperbronze flake, micaceous iron oxide, mica flake, etc.);

organic pigments such as natural organic pigments (cochineal lake,madder lake, etc.); and

synthetic organic pigments such as nitroso pigments (naphthol green Y,naphthol green B, etc.), nitro pigments (naphthol yellow S, pigmentchlorine, lithol fast yellow GG, etc.), pigment-type azo pigment(toluidine red, Hansa yellow, naphthol AS-G, etc.), azo lakes made ofwatersoluble dyes (Persian orange, ponceau 2R, Bordeaux B, etc.), azolakes made of insoluble dyes (lithol red, bone maroon, red lake, etc.),lakes made of basic dyes (fanal color, etc.), lakes made of acid dyes(acid green lake, peacock blue lake, etc.), xanthan lakes (eosin, etc.),anthraquinone lakes (alizarin lake, purpurin lake, etc.), pigments madeof vat dyes (indigo, argon yellow, etc.), and phthalocyanine pigments(phthalocyanine blue, phthalocyanine green, etc.).

Examples of the pigment dispersers include various types of surfactantslisted above as emulsifiers [anionic surfactants, cationic surfactants,nonionic surfactants, and amphoteric surfactants], and polymeremulsifiers (Mn=1,000 to 20,000).

Examples of the viscosity regulators include thickeners, such asinorganic viscosity regulators (sodium silicate, bentonite, etc.),cellulose-based viscosity regulators (methyl cellulose, carboxymethylcellulose, hydroxymethyl cellulose, etc., having Mn of 20,000 or morenormally), protein-based viscosity regulators (casein, casein soda,casein ammonium, etc.), acrylic viscosity regulator (sodiumpolyacrylate, ammonium polyacrylate, etc., having Mn of 20,000 or morenormally), and vinyl-based viscosity regulators (polyvinyl alcohol,etc., having Mn of 20,000 or more normally). Acrylic viscosityregulators and vinyl-based viscosity regulators are preferred.

Examples of the antifoaming agents include long-chain alcohols (octylalcohol, etc.), sorbitan derivatives (sorbitan monooleate, etc.), andsilicone oil (polymethyl siloxane, polyether-modified silicone,fluorine-modified silicone, etc.). Examples of the preservatives includeorganic nitrogen sulfur compound-based preservatives, organic sulfurhalogen compound-based preservatives, etc. Examples of the deteriorationinhibitors and the stabilizers (UV absorbers, antioxidants, etc.)include hindered phenol-based agents, hindered amine-based agents,hydrazine-based agents, phosphorus-based agents, benzophenone-basedagents, benzotriazole-based agents, etc. Examples of the freezinginhibitors include EG, PG, etc.

The amounts to be used of these components vary with the purpose of use,but generally, in the case of a pigment-based paint, it includes the (B)of 10 to 300 parts (solid matters: components other than the aqueoussolvent, this also applies hereinafter), a viscosity regulator of 0 to 5parts, an antifoaming agent of 0 to 6 parts, a preservative of 0 to 5parts, a deterioration inhibitor or stabilizer of 0 to 5 parts, and afreezing inhibitor of 0 to 5 parts, with respect to 100 parts of apigment. In the case of a clear-type paint, generally it includes anantifoaming agent of 0 to 3 parts, a preservative of 0 to 3 parts, a UVabsorber of 0 to 3 parts, and a freezing inhibitor of 0 to 8 parts, withrespect to 100 parts (solid matters) of the (B).

The pigment-type aqueous paint can be produced by, for instance, mixinga dispersing agent for a pigment in the (B) of the present invention,adding a pigment thereto so that the pigment is dispersed, adding otheradditives as required, and filtering the same so that non-dispersedsubstances are removed. For the foregoing dispersion, a dispersingmachine (an atomizer mill, a beads mill, a three-roll mill, a ball mill,etc) can be used.

The paint made of the (B) of the present invention can be coated by ausual painting means (spray painting, brush painting, roll painting,etc.). The viscosity of the paint is selected appropriately according tothe painting method. For instance, in the case of spray painting, theviscosity is preferably 20 mPa·s to 50 mPa·s at a shear rate of 1000s⁻,and 180 mPa·s to 280 mPa·s at a shear rate of 10s⁻¹. In the case where apaint has a viscosity of not more than 50 mPa·s at a shear rate of1000s⁻¹, the paint easily is jetted by a spray, while in the case wherea paint has a viscosity of not less than 180 mPa·s at a shear rate of10s⁻¹, the paint does not tend to sag. These viscosities are measured byusing a High Shear Viscometer (“HSV-2” manufactured by Nippon Seiki Co.,Ltd.).

The paint made of the (B) of the present invention can be applieddirectly or via a primer over an item to be coated, and can be appliedin a single layer or in multiple layers (2 to 8 layers) through repeatedcoating steps. The paint can be used as any one of a primer, anintermediate coat, and a topcoat. Examples of the item to be coatedinclude wood, paper, leather, metals (aluminum, iron, copper, variousalloys, etc.), plastics (vinyl chloride-based resins, acrylic resins,styrene-based resins, etc.), and inorganic materials (concrete, slate,calcium silicate plates, etc.). Examples of a form of the item to becoated include films, fibers, non-woven fabrics, sheets, plates, bars,pipes, blocks, various molded products, built products, etc.

The paints made of the (B) of the present invention suitably are appliedin various paints and coating agents (topcoats, intermediate coats, andprimers for automobiles, paints for construction materials,anticorrosive coatings for metals and the like, mar-proof coatings formetals, resins, and the like, water-proof coatings, solvent-resistantcoatings, and moisture-proof coatings for paper, leather, and the like,and polishing coatings for floors, etc.), and various binders (bindersfor automobile paints, binders for exterior paints, binders for enamelpaper, binders for ceramics, etc.). The amount of a paint to be appliedvaries with the use and purpose, but normally it is 0.5 to 1000 g/m²,preferably 1 to 300 g/m² in the form of an aqueous paint itself (in awet state).

The drying after coating is performed under a condition of approximatelynormal temperature to 200° C. The method for drying is not particularlylimited, and for instance, hot-air, infrared radiation, and electricheaters can be used.

Adhesives

The (B) of the present invention can be used as a main component in anadhesive.

A crosslinking agent can be added to an adhesive with a view to causingthe adhesion function to be delivered more efficiently. Besides, otheradditives such as a pigment, a dispersing agent for a pigment, aviscosity. regulator, a stabilizer, a preservative, and a freezinginhibitor may be added thereto as required. Examples of the crosslinkingagent and the additives include the same ones as those listed aboveregarding the above-described paints.

The amount of the added crosslinking agent is normally 0% to 100%,preferably 3% to 30% with reference to the weight of the (b) in the (B).In the case where the crosslinking agent is not less than 3%, sufficientadhesion strength and durability are obtained, and in the case where itis not more than 30%, items to be bonded do not become-brittle, which ispreferable. The method for mixing the (B) and the crosslinking agent isnot particularly specified, and examples of the method include a mixingmethod by normal stirring, a mixing method using a mixer (a paintconditioner, a ball mill, a kneader, a sand grinder, a flat stone mill,etc.).

Examples of means for applying an adhesive to items to be bonded includebrushing, rolling, spraying, flow coat, and immersion. The bonding canbe performed by applying an adhesive to one of items to be bonded, andattaching the same in the as-is state (without being dried) to the otheritem to be bonded (wet bonding), or attaching the item after being driedto the other item (dry bonding) and hardening the adhesive layer.Alternatively, the bonding may be achieved by interposing a driedadhesive film between the items to be bonded and hardening the same. Thehardening can be achieved by curing the adhesive at normal temperatureor an increased temperature (for instance, approximately 60° C. to 80°C.), or alternatively, by curing the same at normal temperature andthereafter increasing the temperature to approximately 60° C. to 80° C.so as to accelerate the hardening.

The items to be bonded are not limited particularly, and the adhesivescan be applied widely to substrates of various materials such as wood,resin films, rubber, leather, paper, metals, etc.

The adhesives made of the (B) of the present invention are suitablyapplied in, for instance, woodworking adhesives, metalworking adhesives,adhesives for use with plastics, adhesives for use with substrates forelectronic apparatuses, and adhesives for use with fabrics.

Fiber-treating Agents

The (B) of the present invention can be used widely in fiber-treatingbinders (binders for pigment print, binders for use with non-wovenfabrics, binders for the bundling of reinforcing fibers, binders for usein antimicrobial agents, etc.), and fabric coatings (waterproofcoatings, water-repellent coatings, soil-resistant coatings, etc.).

In the case where the (B) is used as the pigment-print binders, one ortwo, or more of an emulsifier, a stabilizer (UV absorber, antioxidant,etc.), a thickener, a film-forming assistant, and other assistants canbe added to the (B) as required. Examples of the emulsifier include thesame ones as the emulsifiers listed above. The anionic surfactants andnonionic surfactants are preferred particularly. Examples of thestabilizer and the thickener include the same ones as those listed aboveregarding the paints. Examples of the film-forming assistant includeN-methyl-2-pyrrolidone, etc. Examples of the other assistants includeprintability-imparting agents, antigumming agents, etc.

The pigment textile-printing can be performed by printing fabrics in thesame way as that for normal pigment print. More specifically, forinstance, a printing paste is prepared by mixing a color paste (waterand a pigment dispersed therein finely and homogeneously), the (B) ofthe present invention, a thickener, and other assistants, andsubsequently, the printing paste is printed on a fabric. For the mixing,a paddle-type mixing vessel or the like is used. For the printing, anautoscreen textile-printing machine, a rotary screen textile-printingmachine, a roller textile-printing machine, and the like can be used. Asthe fabric, fabrics of natural fibers (cotton, hemp, wool, silk, etc.),semi-synthetic fibers (rayon, acetate, etc.), synthetic fibers(polyester, polyamide, polyacrylonitrile, polyolefin, etc.) and the likecan be used.

Examples of the reinforcing fibers subjected to the application of the(B) as a binder for the bundling of reinforcing fibers include inorganicfibers (glass fiber, carbon fiber, etc.), and high-strength organicfibers (polyamide fiber, polyester fiber, etc.).

In the case where the (B) of the present invention is used as a bundlingagent for glass fiber, one or two, or more additives may be added to the(B) as required, examples of which include silane coupling agent(γ-aminopropylethoxysilane, γ-methacryloxy propyltrimethoxysilane, vinyltrichlorosilane, vinyl triethoxysilane, γ-glycidoxypropyltrimethoxysilane, etc.), lubricants (fatty acid amides, soap,etc.), antistatic agents (the surfactants described above, etc.),plasticizers (phthalic acid esters, adipic acid esters, etc.), andantifoaming agents (those described above).

The bundling agent may be used in combination with another bundlingagent, examples of which include starch, processed starch, dextrin,amylose, gelatin, carboxymethyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate, aqueous polyester resins, aqueous epoxyresins, and aqueous acrylic resins. The (B) and arbitrary additives aremixed so that a treating liquid is prepared, and the liquid is appliedto a fiber, and heated and dried as required so that it is fixed. Forthe mixing, a mixing vessel (paddle-type or the like) is used. Theconcentration of the treating liquid is normally 1% to 10%. The treatingliquid is applied to fibers through roller coating, spray coating,impregnation coating, etc. The amount of the same adhering to fibers isnormally 0.1% to 10%. Drying and fixing are performed with, forinstance, hot air at 50° C. to 100° C.

In the case where the (B) is used as a binder for an antimicrobial agentor a coating, the additives, the concentration of a treating liquid, themeans for application of the same to fibers, the amount of the sameadhering to fibers, and treating conditions may be the same as thosedescribed above, and appropriately selected according to the purpose ofuse.

Sheet Materials

The (B) of the present invention can be used widely as a raw materialfor leatherlike sheet materials such as synthetic leathers andartificial leathers.

In the case where a leather-like sheet material is obtained throughimpregnating or coating a fabric material substrate with the (B) andcausing heat-sensitive coagulation, a polyurethane resin aqueousdispersion (B1) for use in sheet materials that satisfy all therequirements (1) to (4) described below is applicable suitably as the(B):

(1) being composed of an anionic polyurethane resin (b1) having one ormore groups selected from the group consisting of —COO^(—)group and —SO₃^(—)group, the group being preferably 0.01% to 8% based on a weight ofthe polyurethane resin;

(2) containing a nonionic surfactant (C) having a HLB of 10 to 18, thesurfactant being preferably 0.1% to 10% based on the weight of thepolyurethane resin;

(3) containing an inorganic salt (D) of preferably 0.1 wt % to 10 wt %;

(4) either not containing a solvent, or containing a solvent of not morethan 5,000 ppm based on the weight of the polyurethane resin.

The lower limit of the content of the at least one group selected fromthe group consisting of —COO^(—)group and —SO₃ ^(—)group, described in(1) above, is more preferably 0.3%, further more preferably 0.4%, andparticularly preferably 0.5%, while the upper limit of the same is morepreferably 6%, further more preferably 5%, and particularly preferably4%. In the case where the content of the foregoing groups is not lessthan 0.01%, the aqueous dispersion exhibits particularly excellentstorage stability, while in the case where the content is not more than8%, a resin coating to be formed exhibits particularly excellentwaterproofness.

Examples of the (C) include, among the nonionic surfactants, thosehaving a HLB of 10 to 18. Among these, AO (C: 2 to 8) adducts ofaliphatic alcohols are further preferred, and those expressed by thefollowing general formula (1) are particularly preferred:R—O—(CH₂CH₂O—)_(x)—H   (1)where R represents a straight-chain or branched alkyl group or alkenylgroup having 4 to 24 carbon atoms, and x represents an integer of 5 to40, preferably 7 to 30.

Examples of the alkyl group include butyl group, isobutyl group, pentylgroup, hexyl group, octyl group, nonyl group, decyl group, lauryl group,cetyl group, stearyl group, etc., while examples of the alkenyl groupinclude octenyl group, decenyl group, dodecenyl group, oleyl group, etc.Among these, lauryl group, cetyl group, and oleyl group are preferred.

The lower limit of the content of the (C) is normally 0.1%, preferably2%, and more preferably 4%, while the upper limit of the same isnormally 10%, preferably 9%, and more preferably 8% based on the weightof the polyurethane resin. In the case where the content of the (C) isnot less than 0.1%, coagulation at room temperature hardly occurs,whereby particularly excellent workability is exhibited, while in thecase where the content is not more than 10%, quick heat-sensitivecoagulation is exhibited. It should be noted that the content of the(C), which is in the range of 0.1% to 10%, is in the same range in thecase where it is based on a weight of a prepolymer.

Regarding the use of the (C), it is more preferable to use a combinationof two or more of the foregoing examples of the (C), for instance, acombination of a nonionic surfactant (C1) having a HLB of 14 to 18 and anonionic surfactant (C2) having a HLB of not less than 10 and less than14.

The lower limit of the HLB of the (C1) is normally 14, preferably 14.2,and particularly preferably 14.4, while the upper limit of the same isnormally 18, preferably 17.8, and particularly preferably 17.6. In thecase where the HLB of the (C1) is not less than 14, the aqueousdispersion exhibits particularly excellent storage stability (effect ofallowing no coagulated matters to develop). On the other hand, in thecase where the HLB is not more than 18, the aqueous dispersion exhibitsa particularly excellent heat-sensitive coagulation property.

The lower limit of the HLB of the (C2) is normally 10, preferably 10.2,and particularly preferably 10.4, while the upper limit of the same isnormally less than 14, preferably 13.8, and particularly preferably13.6%. In the case where the HLB of the (C2) is not less than 10,coagulation at room temperature hardly occurs, whereby particularlyexcellent workability is exhibited, while in the case where the LHB ofthe same is less than 14, quick heat-sensitive coagulation is exhibited.

Regarding the respective contents of the (C1) and the (C2), based on theweight of the polyurethane resin, the lower limit thereof is preferably0.05%, more preferably 1%, and particularly preferably 2%, while theupper limit of the same is preferably 9%, more preferably 8%, andparticularly preferably 7%. The weight ratio of (C1)/(C2) is preferably1/10 to 10/1, more preferably 2/8 to 8/2, particularly preferably 3/7 to7/3.

Preferable examples of the (C1) are those having x in the formula (1) of7 to 30, for instance, polyoxyethylene (degree of polymerization:11)lauryl ether (HLB=14.4: hereinafter abbreviated as LE11),polyoxyethylene (degree of polymerization:18) cetyl ether (HLB=15.0:hereinafter abbreviated as CE18), polyoxyethylene (degree ofpolymerization:24) cetyl ether (HLB=16.1: hereinafter abbreviated asCE24), and polyoxyethylene (degree of polymerization:18) oleyl ether(HLB=15.1: hereinafter abbreviated as OE18), etc. Preferable examples ofthe (C2) are those having x in the formula (1) of 6 to 20, for instance,polyoxyethylene (degree of polymerization: 7) lauryl ether (HLB=12.4:hereinafter abbreviated as LE7), polyoxyethylene (degree ofpolymerization:9) lauryl ether (HLB=13.6: hereinafter abbreviated asLE9), polyoxyethylene (degree of polymerization:7) oleyl ether(HLB=10.8: hereinafter abbreviated as OE7), etc.

The (C) may be added either during the production of the (A) or thepolyurethane resin aqueous dispersion, or after the same, but it ispreferable to add and mix the same after the production of thepolyurethane resin aqueous dispersion from the viewpoint of the storagestability of the polyurethane resin aqueous dispersion.

The (B1) preferably contains an inorganic salt (D) so that theheat-sensitive coagulation property is imparted thereto.

Examples of the (D) include inorganic acid salts or halogenides ofalkali metals or alkaline-earth metals. Examples of inorganic acid saltsof alkali metals include sodium carbonate, sodium sulfate (Na₂SO₄),sodium nitrate, potassium carbonate, etc. Examples of halogenides ofalkali metals include potassium chloride, lithium chloride, sodiumchloride, etc. Examples of inorganic acid salts of alkaline-earth metalsinclude calcium sulfate, magnesium sulfate, magnesium nitrate, calciumphosphate, etc. Examples of halogenides of alkaline-earth metals includecalcium chloride (CaCl₂), magnesium chloride, etc.

Regarding the content of the (D), based on the weight of thepolyurethane resin, the lower limit thereof is normally 0.1%, preferably0.5%, and further preferably 1%, while the upper limit thereof isnormally 10%, preferably 8%, and further preferably 6%. In the casewhere it is not less than 0.5%, particularly excellent effect ofheat-sensitive coagulation is exhibited. Further, in the case where itis not more than 9%, particularly excellent storage stability isexhibited.

The (D) may be added either during the production of the polyurethaneresin aqueous dispersion, or after the same, but it is preferable to addand mix the same after the production of the polyurethane resin aqueousdispersion from the viewpoint of the storage stability of thepolyurethane resin aqueous dispersion.

Further, the (D) may be added in the as-is state or in a state of anaqueous solution of the same. Among these, the addition of the same inthe aqueous solution state is preferred, and the addition of an aqueoussolution containing the foregoing (C) and (D) is particularly preferred.The concentration of the (D) in an aqueous solution is not particularlylimited as long as it is not higher than the solubility of the (D).

The (B1) either does not contain a solvent, or contains a solvent sothat the content of the solvent is not more than 5,000 ppm, preferablynot more than 3,000 ppm, based on the weight of the polyurethane resin,but more preferably no solvent is contained. It should be noted thatregarding the specification of the content of the solvent, the samerange applies to the content of a solvent based on the weight of aprepolymer.

To the (B1), the above-described colorants, UV absorbers, antioxidants,crosslinking agents, inorganic fillers, and known coagulation regulators[higher alcohols (for instance, decyl alcohol, dodecyl alcohol, cetylalcohol, etc. described in JP-B-42(1967)-22719)] may be added asrequired. The sum of the additives is preferably not more than 5% basedon the weight of the polyurethane resin.

The (B1) may be diluted with water so as to be suitable for the moldingof a sheet material, in which the concentration of solid matters ispreferably 5% to 40%, more preferably 10% to 30%.

The heat-sensitive coagulation temperature (T) [° C.] of the (B1) ispreferably not lower than 40° C. from the viewpoint of the storagestability, and is preferably not higher than 80° C. with a view topreventing polyurethane resin from migrating to a surface of a fibersubstrate upon drying with heat. The temperature is further preferably50° C. to 70° C. The (T) in the present invention can be measured by thefollowing method:

10 g of the (B1) diluted so that the concentration thereof is 20% isweighed in a test tube (internal diameter:18 mm), heated at a rate of10° C./min in hot water bath at 90° C. without being stirred, and atemperature at which the foregoing aqueous dispersion loses flowabilityand becomes in a gel state is the temperature (T).

As a fiber material substrate used in a leather-like sheet material,known fiber materials such as non-woven fabrics and knitted or wovenfabrics can be used.

The non-woven fabric may be a fabric with a knitted or woven fabric orthe like laminated in the inside or on a surface thereof forreinforcement or other purposes. As a component fiber of the same, anyof natural fibers and chemical fibers can be used. Examples of thenatural fibers include cotton, wool, silk, and asbestos, and examples ofchemical fibers include regenerated fibers such as rayon and “Tencel”(Lyocell), and semi-synthetic fibers such as acetate and triacetate,synthetic fibers such as polyamide, polyester, polyolefin, and acryl.Alternately, the foregoing fibers may be used in mixture.

The production of the leather-like sheet material of the presentinvention is performed normally through the step of impregnation orcoating of the fiber material substrate with the (B1), the step ofcoagulation by heating, and the step of drying, which are carried out inthe stated order.

After the impregnation or coating, a treatment such as washing withwater may be performed as required. In the case of the impregnation, theimpregnation may be followed by squeezing with a mangle or the like sothat an adhering amount of the (B1) is adjusted. The coating is carriedout by knife coating, air-knife coating, roll coating, spray coating, orthe like. Examples of the method of coagulation by heating include (1)the heating coagulation method of blowing heated water vapor, and (2)the method of introducing the substrate with the (B1) into a drier inthe as-is state so as to be coagulated by heating and dried at the sametime.

The temperature for the heating coagulation in an actual process isrequired to be 10 or more degrees higher, preferably 20 or more degreeshigher, than the (T) of the (B1). By setting the temperature to 10 ormore degrees higher than the (T), a further improved migrationpreventing effect can be achieved.

The temperature for the heating coagulation and the drying is preferably50° C. to 150° C., and more preferably 60° C. to 140° C. After theheating coagulation, a treatment such as washing with water may beperformed as required.

The ratio of solid matters of the (B1) adhering to the fiber materialsubstrate after drying is preferably 3 parts to 150 parts, and morepreferably 20 parts to 120 parts with respect to 100 parts by weight ofthe fiber material substrate.

The sheet materials of the present invention have appropriateflexibility and excellent texture similar to natural leather, and hence,they are of significant use as leather-like sheet materials.

The sheet materials of the present invention can be used suitably forvarious purposes, for instance, mattresses, linings of bags, clothes,core materials for shoes, textiles for cushions, interior materials forautomobiles, materials for wall coverings, etc.

EXAMPLES

The following more specifically describes the present invention by wayof examples, but the present invention is not limited thereto.

It should be noted that a kneader I used in Examples and ComparativeExamples described below was a fixed-container horizontal-axiscontinuous kneader (“KRC kneader S5” manufactured by Kurimoto, Ltd.,maximum operation power:16,000 KW/m³), and a kneader II was arotor/stator dispersing machine (“Ebara Milder MDN-303V” manufactured byEbara Corporation, maximum operation power:1,000 KW/m³).

The conditions of gas chromatography in measuring the content of asolvent were as follows:

-   Device: “GC-14B” manufactured by Shimadzu Corporation-   Column:2m packed column filled with polyethylene glycol 20M    (manufactured by Shinwa Chemical Industries, Ltd.)-   Column temperature: retention at 60° C. for 10 minutes, then,    heating at a rate of 10° C./min, and retention at 180° C. for 30    minutes.-   Internal standard: dioxane or acetone-   Injection temperature:250° C.-   Detector temperature:250° C.

Production Examples 1 to 6 Production of the Prepolymers (a)

According to the formulations (parts) shown in Table 1, raw materialcomponents were put in a stainless autoclave equipped with athermometer, an agitator, and nitrogen blowing pipe. After substitutionwith nitrogen, the components were caused to react under the conditionsof the temperatures and reaction times shown in Table 1 while beingagitated, whereby isocyanate group-terminated prepolymers (a-1) to (a-6)were obtained. Viscosities and NCO contents (%) of the same are shown inTable 1.

Examples 1 to 5, Comparative Examples 1 to 4 Prepolymer AqueousDispersions

Kneaders and raw materials shown in Table 2 and 3 were used. The (a)whose temperature was adjusted to 50° C. in an autoclave was fed to thekneader by using a gear pump, while a dispersion medium (water orsurfactant aqueous solution) at 20° C. was fed from another tank to thekneader by using a diaphragm pump, at a flow rate shown in Table 2 or 3,so that they were brought into contact and kneaded. By so doing,prepolymer aqueous dispersions (A-1) to (A-5), and (A-6x) to (A-9x) wereobtained. The solid component concentrations, viscosities, averageparticle diameters, and contents of particles having sizes of not lessthan 5,000 nm, of the foregoing prepolymer aqueous dispersions are shownin Tables 2 and 3.

Examples 6 to 10, Comparative Examples 5 and 6 Polyurethane ResinAqueous Dispersions

Prepolymer aqueous dispersions shown Tables 4 and 5, and an aqueoussolution of the (E) whose temperature was adjusted to 30° C. were fed tothe kneader II at a flow rate shown in Table 4 or 5 so that the aminogroups (—NH₂) were 0.6 mole with respect to 1 mole of isocyanate groups(—NCO group) of the prepolymer (a), and were mixed by agitation at 6,000rpm, whereby polyurethane resin aqueous dispersions (B-1) to (B-5),(B-6x) and (B-7x) were obtained.

Analyzed values, storage stability, and waterproofiess of films of theforegoing materials are shown in Tables 4 and 5.

Evaluation of Storage Stability:

An aqueous dispersion was left to stand in a 100-ml glass bottle at roomtemperature for three months, and the presence/absence of settling wasdetermined by visual observation. “⊚” indicates that no settling wasobserved. “◯” indicates that a small amount of settling was observed butre-dispersed when the bottle was shaken. “x” indicates that settling wasobserved and did not re-disperse when the bottle was shaken.

Evaluation of Waterproofness:

The aqueous dispersion was coated over a glass plate so that it wouldhave a film thickness of approximately 200 μm after being dried, andfilms obtained after drying at 25° C. for 24 hours, drying at 80° C. for3 hours, and drying at 130° C. for 45 minutes were immersed in water at25° C. for 48 hours. Changes in the appearance of the films were checkedby visual observation. “⊚” indicates that no change in an appearance wasobserved. “◯” indicates that a slight change of whitening was observed.“x” indicates that peel-off and whitening occurred.

<Production of Non-woven Fabrics>

A laminate sheet was formed with a polyethylene terephthalate staplefiber, and the sheet was needle-punched at a rate of 280 needles percm². and a non-woven fabric with a weight of 380 g/m² and an apparentdensity of 0.18 g/cm³ was obtained.

Examples 11 to 13, Comparative Examples 7 to 10 Leather-like Sheetmaterial

The samples of the (C) and (D) shown in Table 6 or 7, dissolved ordispersed in 20 parts of water, were mixed in 200 parts of the (B) shownin Table 6 or 7, and water further was added thereto so that theconcentration was 25%, whereby urethane resin aqueous dispersions forsheet materials (B1-1) to (B1-3) and (B1-4x) to (B1-7x) were obtained.The heat-sensitive coagulation temperatures of these dispersions areshown in Tables 6 and 7. It should be noted that the comparativeexamples 7 and 9 coagulated immediately after the (B1-4x) and (B1-6x)were formed, and hence, their heat-sensitive coagulation temperaturewere not measured.

The above-described non-woven fabrics were immersed in the (B1) [exceptfor the (B1-4x) and the (B1-6x)], and were squeezed with a mangle sothat a ratio of solid portions adhering thereto was 50±2 wt % withrespect to the weight of the non-woven fabric. Then, the fabrics wereplaced in saturated water vapor at 100° C. for 2 minutes so thatheat-sensitive coagulation occurred, and subsequently dried at 100° C.for 20 minutes by a hot-air drier, whereby leather-like sheet materialswere obtained.

The obtained sheet materials were evaluated by the following evaluationmethod, and the results of the evaluation are shown in Tables 6 and 7.

<Evaluation Method>

[Ratio of Resin Adhering to Fabric]

The ratio was calculated by the following formula regarding theleather-like sheet materials after drying.

$100 \times {\frac{\begin{matrix}{\left( {{weight}\mspace{14mu}{of}\mspace{14mu}{leather}\text{-}{like}\mspace{14mu}{sheet}} \right) -} \\\left( {{weight}\mspace{14mu}{of}\mspace{14mu}{fiber}\mspace{14mu}{material}\mspace{14mu}{substrate}} \right)\end{matrix}}{\left( {{weight}\mspace{14mu}{of}\mspace{14mu}{fiber}\mspace{14mu}{material}\mspace{14mu}{substrate}} \right)}\left\lbrack {{unit}\text{:~~}{wt}\mspace{14mu}\%} \right\rbrack}$[Presence/absence of Migration]

Cross-sections of sheets were observed by an electron microscope(“S-800” manufactured by Hitachi, Ltd.) so that adhesion of thepolyurethane resins to surface portions and central portions thereofwere checked. The sheets in which the polyurethane resin was distributedhomogeneously in fiber material substrates, which means that migrationdid not occur, were evaluated as “◯”, and the sheets in which thepolyurethane resin was unevenly distributed, mainly in the vicinities ofsurfaces of the fiber material substrates, which means that migrationoccurred, were evaluated as “x”.

[Texture]

The sheets having texture like natural leather were evaluated as “◯”,those having flexibility slightly inferior to that of natural leatherwere evaluated as “Δ”, and those which lacked flexibility and hence didnot have texture like natural leather were evaluated as “x”. Theevaluation was performed by sensory testing with hand touch.

[Air Permeability]

A time (seconds) that was required for air of 50 ml to permeate theleather-like sheet of the present invention was measured by using aGurley densometer according to the method of JIS P8117.

[Porousness]

A cross section of each sheet was observed by visual observation usingan electron microscope so that whether or not a surface of the urethaneresin filled was porous was determined. Those having porous surfaces ofthe urethane resin were evaluated as “◯”, while those having non-poroussurfaces of the urethane resin were evaluated as “x”.

TABLE 1 Production Example No. 1 2 3 4 5 6 Type of (a) a-1 a-2 a-3 a-4a-5 a-6 Number of parts (a1) IPDI 666 666 — — 666 666 (Molar ratio) (3)(3) (3) (3) HDI — — 504 — — — (3) TDI — — — 522 — — (3) (a2) PC 2000 — —2000 2000 2000 (1) (1) (1) (1) PES — 2000 2000 — — — (1) (1) (a3) BG — —— — 90 90 (1) (1) (a4) DMPA 134 134 134 134 26.8 — (1) (1) (1) (1) (0.2)TEA 101 101 101 101 20 — (Neutralizer) (1) (1) (1) (1) (0.2) DHS — 2.2 —— — — (0.01) Solvent NMP — 8.8 — — — — Content of ionic groups (%) 1.61.6 1.7 1.7 0.3 0 Reaction temperature (° C.) × time (hrs) 50 × 8 50 × 850 × 8 50 × 3 80 × 8 100 × 8 Analyzed value Viscosity 400 300 150 600350 200 (Pa · s) (at 60° C.) NCO(%) 2.7 2.7 3.0 3.0 2.4 3.0

TABLE 2 Example No. 1 2 3 4 5 Type of (A) (A-1) (A-2) (A-3) (A-4) (A-5)Kneader Type I I I I I Revolution(rpm) 250 250 250 250 250 OperationPower (KW/m³) 4,300 5,000 4,300 4,800 4,000 Material (a) Type a-1 a-2a-3 a-4 a-5 and Flow 20 20 20 20 20 Flow rate rate Dispersion Type WaterWater Water Water 3% aqueous medium solution of CE18 Flow 9 9 9 9 9 rateKneading Temperature (° C.) 60 60 60 60 60 Viscosity (Pa · s) of (a) atkneading 400 300 150 600 350 temperature Residence time (sec.) 20 20 2020 20 Analyzed Concentration of solid 69 69 69 69 70 values matters (%)Viscosity (Pa · s) (at 25° C.) 2.0 1.5 1.5 2.0 0.5 Content of Surfactant(%) 0 0 0 0 1.4 Content of solvent (%) 0 0.2 0 0 0 Average particlediameter (nm) 60 80 75 60 250 Content of particles with 0 0 0 0 0.2particle diameter of 5,000 nm or more (%) Unit of flow rate: L/hr

TABLE 3 Comparative Example No. 1 2 3 4 Type (A-6x) (A-7x) (A-8x) (A-9x)Kneader Type II II II II Revolution(rpm) 10,000 6,000 10,000 10,000Operation Power 400 150 300 250 (KW/m³) Material (a) Type a-1 a-1 a-6a-6 and Flow 20 20 20 20 Flow rate rate Dispersion Type Water Water 10%aqueous 25% medium solution of aqueous CE18 solution of CE18 Flow 9 30 916 rate Kneading Temperature (° C.) 60 60 60 60 Viscosity (Pa · s) of(a) at 400 400 200 200 kneading temperature Residence time (sec.) 12 1020 20 Analyzed Concentration of Revolution 40 Coagulation 67 valuessolid matters (%) stopped 3 mins occurred Viscosity (Pa · s) afterkneading 0.08 immediately 2.0 (at 25° C.) started, and after Content ofmotor seized 0 dispersion. 20 Surfactant (%) up. Content of solvent (%)0 0 Average particle 650 300 diameter (nm) Content of particles 10 0.3with particle diameter of 5,000 nm or more (%) Unit of flow rate: L/hr

TABLE 4 Example No. 6 7 8 9 10 Type of (B) (B-1) (B-2) (B-3) (B-4) (B-5)Material and (A) Type (A-1) (A-2) (A-3) (A-4) (A-5) Flow rate Flow rate29 29 29 29 29 (E) Type IPDA IPDA EDA HDH IPDA Concentration (%) 6.0 6.02.3 3.9 4.5 Flow rate 11 11 11 11 13 Molar ratio of NH₂/NCO 0.6 0.6 0.60.6 0.6 Analyzed Concentration (%) 50 50 50 50 50 values Viscosity (Pa ·s) (at 25° C.) 0.40 0.35 0.55 0.65 0.15 Content of surfactant (%) 0 0 00 1.4 Content of solvent (%) 0 0.1 0 0 0 Average particle diameter (nm)65 90 85 70 280 Content of particles with particle diameter 0 0 0 0 0.3of 5,000 nm or more (%) Storage Stability ⊚ ⊚ ⊚ ⊚ ⊚ Waterproofness ⊚ ⊚ ⊚⊚ ◯ Unit of flow rate: L/hr

TABLE 5 Comparative example No. 5 6 Type (B-6x) (B-7x) Material and (A)Type (A-7x) (A-9x) Flow rate Flow rate 50 36 (E) Type IPDA IPDAConcentration (%) 9.4 5.7 Flow rate 7 13 Molar ratio of NH₂/NCO 0.6 0.6Analyzed values Concentration (%) 35 50 Viscosity (Pa · s) (at 25° C.)0.03 0.70 Content of surfactant (%) 0 20 Content of solvent (%) 0 0Average particle diameter (nm) 800 340 Content of particles with 15 0.5particle diameter of 5,000 nm or more (%) Storage Stability X ◯Waterproofness ◯ X Unit of flow rate: L/hr

TABLE 6 Example 11 12 13 Type of (B1) (B1-1) (B1-2) (B1-3) Material and(B) (B-1) (B-1) (B-5) the number (200) (200) (200) of parts (C) (C1)CE24 LE11 CE18 (4) (6) (0.5) (C2) LE7 OE7 LE9 (4) (2) (3) (D) Na₂SO₄CaCl₂ CaCl₂ (3) (2) (1) Heat-sensitive coagulation 65 47 50 temperature(° C.) Resin adhesion rate (%) 51 50 48 Migration ◯ ◯ ◯ Texture ◯ ◯ ◯Air permeability (sec.) 4 5 5 Porousness ◯ ◯ ◯

TABLE 7 Comparative Example 7 8 9 10 Type (B1-4x) (B1-5x) (B1-6x)(B1-7x) Material and (B) (B-7x) (B-1) (B-1) (B-1) the number (200) (200)(200) (200) of parts (C) (C1) — CE60 LE11 LE11 (4) (6) (6) (C2) — LE7OE5 OE7 (4) (2) (2) (D) CaCl₂ Na₂SO₄ CaCl₂ — (1) (3) (2) Heat-sensitive— 90 — 90 coagulation or more or more temperature (° C.) Resin adhesion— 52 — 49 rate (%) Migration — X — X Texture — Δ — X Air permeability —18 — 28 (sec.) Porousness — X — X CE60: polyoxyethylene (polymerizationdegree: 60) cetyl ether (HLB = 18.5) OE5: polyoxyethylene(polymerization degree: 5) oleyl ether (HLB = 9.0)Industrial Applicability

The present invention is capable of providing a polyurethane resinaqueous dispersion having excellent storage stability.

Further, the present invention is capable of providing an isocyanategroup terminated prepolymer aqueous dispersion suitably used in theproduction of the foregoing polyurethane resin aqueous dispersion havingexcellent storage stability.

Further, the present invention is capable of providing an isocyanategroup terminated prepolymer aqueous dispersion and a polyurethane resinaqueous dispersion that contain either nothing of, or small amounts of,a surfactant and a solvent.

The polyurethane resin aqueous dispersion of the present invention hasexcellent characteristics of less flammability, a high level of safetyto the human body, and environmental friendliness. Further, thepolyurethane resin aqueous dispersion of the present invention can beused in a polyurethane resin sheet material, a paint, an adhesive, atackiness agent, or a fiber-treating agent possessing waterproofliess.Still further, the polyurethane resin aqueous dispersion of the presentinvention can be used in a leather-like polyurethane resin sheetmaterial in which migration is prevented.

1. An isocyanate group terminated prepolymer aqueous dispersion (A),comprising: water; and a prepolymer(a) terminated with an isocyanategroup, the (a) being dispersed in the water, a content of the (a) in the(A) being in a range of 60 wt % to 85wt %, wherein the (A) either doesnot contain a surfactant or contains a surfactant of not more than 10 wt% based on a weight of the (a), and either does not contain a solvent orcontains a solvent of not more than 5,000 ppm based on the weight of the(a).
 2. The prepalymer aqueous dispersion according to claim 1, whereinparticles of the (a) dispersed in the water have an average particlediameter of 30 nm to 500 nm, and a content of particles of the samehaving a particle diameter of not less than 5,000 nm is not more than 1vol %.
 3. The prepolymer aqueous dispersion (A) according to claim 1,being obtained by subjecting the isocyanate group terminated prepolymer(a) and the water to contact mixing by employing a kneader having anoperation power of not less than 2000 KW/m₃ so as to disperse the (a) inthe water.
 4. The prepolymer aqueous dispersion according to claim 1,wherein the (a) has a viscosity of 2 Pa·s to 10,000 Pa·s at a kneadingtemperature.
 5. The prepolymer aqueous dispersion according to claim 1,wherein the (a) includes ionic groups of 0.0 1 wt % to 8 wt % based onthe weight of the (a).
 6. A method for producing an aqueous dispersion(A) of claim 1 in which a prepolymer (a) terminated with the isocyanategroup is dispersed, the method comprising: subjecting the (a) and waterto contact mixing by employing a kneader having an operation power ofnot less than 2000 KW/m₃ so as to disperse the (a) in the water, whereinthe (a) either does not contain a surfactant or contains a surfactant ofnot more than 10 wt % based on a weight of the (a), and either does notcontain a solvent or contains a solvent of not more than 5,000 ppm basedon the weight of the (a).
 7. The method according to claim 6, wherein asthe kneader, a multiaxial kneader selected from the group consisting ofa continuous kneader, a taper roll, and an extruder is employed.